Interface control apparatus, data storage apparatus and interface control method

Abstract

According to one embodiment, an interface control apparatus includes an interface, a table, a command processor, and a controller. The interface transmits and receives information to and from a host. The table holds management information for managing an address in a memory space in the host. The command processor carries out a command process of accessing the memory space in the host using the management information. The controller releases the management information corresponding to the command process from the table in response to completion of the command process.

What is claimed is: 
     
       1. An apparatus for interface control comprising:
 an interface configured to transmit and receive information to and from a host; 
 a table configured to hold management information for managing an address in a memory space in the host; 
 a command processor configured to carry out a command process of accessing the memory space in the host using the management information; and 
 a first controller configured to release the management information corresponding to the command process from the table in response to completion of the command process. 
 
     
     
       2. The apparatus of  claim 1 , further comprising:
 a second controller configured to extract request information including the management information and specifying the command process from an element that is a storage unit for queue in the host, and to store the request information in the table in units of the element. 
 
     
     
       3. The apparatus of  claim 2 , wherein the first controller is configured to:
 release, for a second element other than a first element including a header of the request information, second request information corresponding to the second element from the table after the data transfer indicated by the second element is completed; and 
 release, for the first element, first request information corresponding to the first element after the command process is completed. 
 
     
     
       4. The apparatus of  claim 3 , wherein the second controller is configured to store request information corresponding to an element including next management information acquired from a queue after the first controller releases the second request information from the table. 
     
     
       5. The apparatus of  claim 2 , wherein the table comprises a first table storing the management information in units of elements and a second table storing all of the request information in units of elements, and
 the second controller is configured to manage the first table and the second table in association with each other in units of elements. 
 
     
     
       6. The apparatus of  claim 2 , wherein the management information includes an address for accessing the memory space in the host, and
 the command processor is configured to: 
 carry out a process of writing read target data to the memory space in the host specified by address in the management information when the request information acquired by the second controller includes a read command; and 
 carry out a process of reading data on the memory space in the host specified by address in the management information when the request information acquired by the second controller includes a write command. 
 
     
     
       7. A data storage apparatus comprising:
 the apparatus for interface control according to  claim 1 ; 
 a storage medium; and 
 a read write controller configured to write and read data to and from the storage medium based on a command process by the command processor. 
 
     
     
       8. The data storage apparatus of  claim 7 , further comprising:
 a second controller configured to extract request information including the management information and specifying the command process from an element that is a storage unit for queue in the host, and to store the request information in the table in units of the element. 
 
     
     
       9. The data storage apparatus of  claim 8 , wherein the first controller is configured to:
 release, for a second element other than a first element including a header of the request information, second request information corresponding to the second element from the table after the data transfer indicated by the second element is completed; and 
 release, for the first element, first request information corresponding to the first element after the command process is completed. 
 
     
     
       10. The data storage apparatus of  claim 9 , wherein the second controller is configured to store request information corresponding to an element including next management information acquired from a queue after the first controller releases the second request information from the table. 
     
     
       11. The data storage apparatus of  claim 8 , wherein the table comprises a first table storing the management information in units of elements and a second table storing all of the request information in units of elements, and
 the second controller is configured to manage the first table and the second table in association with each other in units of elements. 
 
     
     
       12. The data storage apparatus of  claim 8 , wherein the management information includes an address for accessing the memory space in the host, and
 the command processor is configured to: 
 carry out a process of writing read target data to the memory space in the host specified by address in the management information when the request information acquired by the second controller includes a read command; and 
 carry out a process of reading data on the memory space in the host specified by address in the management information when the request information acquired by the second controller includes a write command. 
 
     
     
       13. A method for interface control applied to an interface control apparatus that transmits information between a host and a data storage apparatus, the method comprising:
 storing management information acquired from the host and allowing management of an address in a memory space in the host; 
 carrying out a command process of accessing the memory space in the host using the management information; and 
 releasing the management information corresponding to the command process in response to completion of the command process. 
 
     
     
       14. The method of  claim 13 , further comprising:
 extracting request information including the management information and specifying the command process from an element that is a storage unit for queue in the host; and 
 storing the request information in units of the element. 
 
     
     
       15. The method of  claim 14 , further comprising:
 releasing, for a second element other than a first element including a header of the request information, second request information corresponding to the second element after the data transfer indicated by the second element is completed; and 
 releasing, for the first element, first request information corresponding to the first element after the command process is completed. 
 
     
     
       16. The method of  claim 15 , further comprising:
 storing request information corresponding to an element including next management information acquired from a queue after the second request information is released. 
 
     
     
       17. The method of  claim 14 , wherein
 the interface control apparatus further comprises a first table storing the management information in units of elements and a second table storing all of the request information in units of elements, and the method further comprising: 
 managing the first table and the second table in association with each other in units of elements. 
 
     
     
       18. The method of  claim 14 , wherein
 the management information includes an address for accessing the memory space in the host, and 
 further comprising: 
 carrying out a process of writing read target data to the memory space in the host specified by address in the management information when the acquired request information includes a read command; and 
 carrying out a process of reading data on the memory space in the host specified by address in the management information when the acquired request information includes a write command.